Proponents of the chemtrail theories differentiate chemtrails from contrails by describing them as streams that sometimes persist in the sky for hours, and which sometimes trace criss-crossing, grid-like patterns, or parallel stripes which eventually blend to form large clouds. Another feature that proponents say distinguishes a chemtrail from a contrail is the presence of visible color prisms in the streams, unusual concentrations of sky tracks in a single area, or lingering tracks left by unmarked or military airplanes flying in atypical altitudes or locations.

Government agencies and other experts on contrail or atmospheric phenomena deny the existence of chemtrails, insisting that the characteristics attributed to them are simply features of contrails responding differently in diverse conditions in terms of the sunlight, temperature, horizontal and vertical wind shear, and humidity levels present at the aircraft's altitude.These experts respond that what appears as patterns such as grids formed by contrails result from increased air traffic traveling through the gridlike United States National Airspace System's north-south and east-west oriented flight lanes, and that it is difficult for observers to judge the differences in altitudes between these contrails from the ground. The jointly published fact sheet produced by NASA, the EPA, the FAA, and NOAA in 2000 in response to alarms over chemtrails details the science of contrail formation, and outlines both the known and potential impacts contrails have on temperature and climate.[The USAF produced a fact sheet as well that described these contrail phenomena as observed and analyzed since at least 1953. It also rebutted chemtrails' theories more directly by characterizing the theories as a hoax and denying the existence of any chemtrails.

Patrick Minnis, an atmospheric scientist with NASA's Langley Research Center in Hampton, Virginia, is quoted in USA Today as saying that logic is not exactly a real selling point for most chemtrail proponents: "If you try to pin these people down and refute things, it's, 'Well, you're just part of the conspiracy', he said."

In 2001, United States Congressman Dennis Kucinich introduced legislation that would have permanently prohibited the basing of weapons in space, and he listed chemtrails as one of a number of exotic weapons that would be banned.Proponents have asserted that because explicit reference to chemtrails was entered by Congressman Kucinich into the congressional record, this constitutes official government acknowledgement of their existence. But that bill received an unfavorable evaluation from the United States Department of Defense and died in committee, with no mention of chemtrails appearing in the text of any of the three subsequent failed attempts by Kucinich to enact a Space Preservation Act.

and no, I'm not saying this is real, I just find conspiracy theories interesting.

I actually noticed that while I was at the park with my girl, when a (what looked like) commercial plane flew over and then turned around and came back.. thought it was kind of strange.